Cart 0

Diagnosing Keg Issues

Leaky kegs can be frustrating.  Fortunately diagnosing kegs issues is, usually, a fairly simple process and repairs are even easier.  For help with the names of different keg parts refer to our Keg Parts Diagrams.

The most common causes of leaks from ball lock and pin lock kegs are:

  1. A leaking Keg Cap.
  2. A leaking Poppet.
  3. A leaking Dip Tube O-Ring.
  4. A leaking Post O-Ring.
  5. A leaking Pressure Relief Valve.

Finding the Problem

To find where your leak is coming from spray down the top of the keg with a foaming sanitizer like Star San and pressurize the keg with CO2.  Look for bubbles coming from all of the areas mentioned above.  Leaking Dip Tube O-Rings show as leaks between the base of the posts and the keg.  You will only be able to see a leaky Post O-Ring with a coupler attached.  Look for leaking between the Coupler and the Post.  A leaky poppet is only visible without a Coupler attached. 

Fixing the Problem

Repairing a leaky keg is best done with the keg empty, however in a pinch any repairs suggested here can be done with beer in the keg.  Just keep plenty of sanitizer on hand to avoid infection.

The first step to solving any keg leak is food safe Keg Lube.  Applied to a leaky O-Ring it usually will seal the gap and get your keg back in working order.  Regularly lubricating your keg's O-Rings during cleaning can prevent leaks before they happen.

If Keg Lube doesn't work or your O-Ring is damaged, dry rotted, or otherwise un-serviceable, replacement O-Rings, Pressure Relief Valves and Poppets are inexpensive and easy to install.

Keg Cap O-Rings

  1. Disconnect the keg from both the gas and liquid couplers.
  2. De-Pressurize the keg.
  3. Open the Keg Cap and remove the Keg Cap O-Ring.  The O-Ring may be stuck to the inside lip of the keg rather than on the Keg Cap.
  4. Apply Keg Lube to the new O-Ring if desired.
  5. The new O-Ring will easily slide into place on the Keg Cap.
  6. Re-install the Keg Cap.  Remember to sanitize first if there's beer in there.
  7. Occasionally a Keg Cap is deformed or the keg itself has become warped or damaged so that a standard Rubber Keg Cap O-Ring won't seal.  For that situation we offer Silicone Keg Cap O-Rings which are a bit softer and provide a more forgiving seal.

Poppets

When changing the Poppet it's a good idea to also replace the Dip Tube O-Ring, since both require removal of the Post.

  1. Disconnect the keg from both the gas and liquid couplers.
  2. De-Pressurize the keg.
  3. Remove the Post taking care not to lose the spring and poppet.
  • For Ball Lock Kegs the Posts are 11/16" or 7/8"  Use either an adjustable wrench or an appropriately sized wrench or deep socket for removal.
  • For Pin Lock Kegs use a specially modified Pin Lock Deep Socket.
  1. With the Post off the keg use needle nose pliers to pull the old poppet and spring out of the Post.  Alternately you can use a small screwdriver or other appropriately sized tool to push the poppet out of the Post from the top.
  2. Place the piston on the spring of the Universal Poppet and push it into the post with the gasket on the piston facing up.
  3. Hand screw the Post back onto the keg, taking care that the Poppet stays in place in the Post.
  4. Tighten the Post with a wrench to compress the Dip Tube O-Ring.

Dip Tube O-Rings

When changing the Dip Tube O-Ring it's a good idea to have a spare Universal Poppet on hand.  Stock poppets are often difficult to re-install if they come loose when removing the Post.

  1. Disconnect the keg from both the gas and liquid couplers.
  2. De-Pressurize the keg.
  3. Remove the Post taking care not to lose the spring and poppet.
  • For Ball Lock Kegs the Posts are 11/16" or 7/8"  Use either an adjustable wrench or an appropriately sized wrench or deep socket for removal.
  • For Pin Lock Kegs use a specially modified Pin Lock Deep Socket.
  1. With the Post out of the way remove the Dip Tube from the keg.  Gas Dip Tubes sometimes stick to the Post when you remove it.
  2. Slide or cut the old Dip Tube O-Ring off the Dip Tube.
  3. Slide the new Dip Tube O-Ring from the bottom to the top of the Dip Tube.
  4. Lubricate the O-Ring if desired.
  5. Slide the Dip Tube back into the Keg.  Remember to sanitize first if there's beer in there.
  6. Hand screw the Post back onto the keg, taking care to replace the Poppet and spring correctly, with the Poppet's gasket pointing out.
  7. Tighten the Post with a wrench to compress the O-Ring.

Post O-Rings

  1. Use a pair of needle nose pliers (if available) to remove the old Post O-Ring.
  2. The new O-Ring will easily snap into place.
  3. Apply Keg Lube to the new O-Ring if desired

Pressure Relief Valves

Assuming you have a standard, manually operable, Pressure Relief Valve they are replaceable.  If you have a non-standard or non-manually operable valve you will need to replace your Keg Cap entirely.

  1. Disconnect the keg from both the gas and liquid couplers.
  2. De-Pressurize the keg.
  3. Unscrew the Pressure Relief Valve from the Keg Cap.
  4. Screw the new Pressure Relief Valve into the Keg Cap.